$Id: README,v 1.4 2001/03/30 12:39:05 gcosmo Exp $
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     =========================================================
     Geant4 - an Object-Oriented Toolkit for Simulation in HEP
     =========================================================

                            TestEm4
                            -------

	This example has been setup to test the low energy gamma processes. 
	
 1- GEOMETRY DEFINITION
 
 	It is a cylinder of 5 cm radius filled with C6F6.
 	
 2- PHYSICS LIST
 
 	The particle list contains only gamma, electron,positron.
 	The physics list contains the 'standard' electromagnetic processes.
 	 
 3- AN EVENT : THE PRIMARY GENERATOR
 
 	The primary kinematic is a single 9 MeV gamma randomly shooted at the
 	middle of the cylinder. 
 	 				
 4- VISUALIZATION
 
 	The Visualization Manager is set in the main().
 	The initialisation of the drawing is done via the command
 	/vis~/create_view in the macro init.mac. This macro is
 	automatically read from the main in case of interactive running mode.
 	
 	The detector has a default view which is a transversal view of the 
 	cylinder.
 	
 	The tracks are drawn at the end of event, and erased at the end of run.
 	Optionaly one can choose to draw all particles, only the charged one,
 	or none. This command is defined in EventActionMessenger class.
 	
 5- PHYSICS SURVEY
 
 	the energy deposited in C6F6 is histogramed (HEP Hist)
 	
 6- HOW TO START ?
 
 	- compile and link to generate an executable
 		% cd examples/extended/electromagnetic/TestEm4
 		% gmake
 		
 	- execute TestEm4 in 'batch' mode from macro files
 		% TestEm4   run01.mac
 		
 	- execute TestEm4 in 'interactive mode' with visualization
 		% TestEm4
 		....
 		Idle> type your commands
 		....
 		Idle> exit
 		
 	- visualize the histogram
 		paw> h/file 1 testem4.paw
 		paw> option stat
 		paw> option logy
 		paw> h/pl 1 	

 Note that, histograms are disabled via the flag G4NOHIST in the GNUmakefile.
 Currently, histograms in this example are implemented through the obsolete
 CLHEP/Hist package, which is no longer supported. The implementation will
 be replaced by direct call to the "analysis" module in a near future.